Machines for inserting small pins in corresponding holes in work pieces are now in common use. According to the particular use requirements, the pins may be either solid cylindrical pins or spring pins. A spring pin is a small cylinder (usually of metal) of selected length and diameter, slit longitudinally so that it can be circumferentially compressed whereby it may be driven into a slightly smaller cylindrical hole.
For examples of machines for inserting small pins in work pieces, see the patents to White U.S. Pat. No. 3,982,679, Dodson et al U.S. Pat. No. 4,333,233 and Erskine U.S. Pat. No. 4,385,719. In the typical situation, the pins are fed vertically to a pin holder and then driven vertically downward into a vertical hole in a horizontally positioned work piece.